British Prime Minister Tony Blair's top aide, Alastair Campbell, has admitted to tinkering with a security report seen as bolstering the campaign for the American-led invasion of Iraq, a confidential letter published Thursday in a London daily showed.

According to AFP, Campbell denied a BBC report that according to an unnamed source, he personally inserted into the document a claim that ousted Iraqi President Saddam Hussein could launch weapons of mass destruction within 45 minutes.

Details of the letter, sent to a parliamentary committee investigating the government's case for war, were leaked to The Guardian newspaper.

The letter is to form a crucial part of the foreign affairs select committee's final assessment, due next Monday, into whether ministers deliberately misled parliament and exaggerated intelligence, against the recommendations of security services, over Iraq's alleged weapons of mass destruction, the daily reported.

The letter is said to have been cleared by the chairman of the joint intelligence committee (JIC), which brings together the chiefs of all British intelligence agencies.

It reveals that Campbell, Blair's director of communications, suggested 11 changes be made to a draft of the Iraq dossier, published in its final form by the British government on September 22, 2002.

According to Campbell's letter, six of his proposed changes were acted upon, four others were not, while the other was already under way.

Amongst changes made were the removal of the words "vivid and horrifying" in the human rights section of the dossier after Campbell deemed them to be unnecessary.

He also questioned why the draft report said Saddam's sons "may have" the authority to launch chemical weapons, instead of "have". But Campbell's request for the removal of the word "may" was turned down by the JIC.

He was also told there was no intelligence to suggest Iraq had secured uranium and that the phrase "sought to secure" would have to remain.

Meanwhile, in a passage dealing with Iraqi dual-use facilities Campbell successfully argued that the phrase "could be used" be replaced with "are capable of being used".

He also successfully proposed that the section detailing how long it might take for Iraq to develop nuclear weapons be more clearly explained.

Campbell, 46, has been called "the real deputy prime minister" and "the second most powerful person in Britain." He entered journalism, rising to edit a new newspaper called Sunday Today at the age of 29. But the publication's launch faltered and the experience led him to have a nervous breakdown.

In 1994, he moved from being political editor of the Daily Mirror to spokesman for Tony Blair, then leader of the opposition. (Albawaba.com)